Fingerprinting and analyzing gemstones

Abstract

The embodiments disclosed herein relate to the examination of gemstones including diamonds, both cut/polished and rough, using the technology of Resonant Ultrasound Spectroscopy. The resonant frequencies are obtained by mechanically causing the stone to vibrate using a swept sine oscillator, sensing the resonance vibrations, and displaying the spectrum to yield a pattern describing the stone. The resonance fingerprints can be used to both track an individual stone to verify its integrity or to grade a rough stone to establish potential value.

What is claimed is: 
     
       1. A method, comprising:
 by a signal generator and a signal processor,
 sending an input signal to a first input transducer, 
 
 wherein the first input transducer is contacting a gemstone under evaluation; 
 receiving a resonance signal from a second receiver transducer,
 wherein the second receiver transducer is contacting the gemstone under evaluation; 
 
 stepping the input signal through a range of sinusoidal input frequencies at a 100 Hz interval, from a range either 1 MHz to 4 MHz if the gemstone is less than one carat size, or from a range 0.2 MHz to 0.3 MHz if the gemstone is greater than one carat in size; 
 receiving a range of received signals; 
 processing, with algorithms, the range of received signals by using a square root of a sum of squares of the received signals for producing graphs of all positive values; 
 determining, by the computer, resonant frequencies of the gemstone by identifying spikes of highest peaks in the display of all positive values; 
 determining how many crystals are included in the gemstone by counting the identified spikes of highest peaks in the display of all positive values; 
 determining a Q rating using the received signals wherein Q is defined as the center frequency of a peak divided by the full width at half maximum of the peak; 
 establishing a unique fingerprint for the gemstone based on the range of received signals and the Q value; 
 determining a weight approximation of the gemstone using a square root of a mass divided by two for a lowest resonance frequency spike detected; and 
 sending the processed range of received signals for the gemstone under evaluation to a computer storage for storage and display of all positive values. 
 
     
     
       2. The method of  claim 1  wherein the input signal is sent from the signal generator to the first transducer through an input amplifier; and
 wherein the received signal is received at the signal processor from the receiver transducer through a receiver amplifier. 
 
     
     
       3. The method of  claim 1  wherein processing the received signal includes in-phase and quadrature components of the received signal. 
     
     
       4. The method of  claim 1  wherein the signal processor includes a phase sensitive detector and digital signal processor. 
     
     
       5. The method of  claim 1  wherein stepping the input signal through a range of input frequencies is stepped by 1 to 1000 Hz. 
     
     
       6. The method of  claim 1  wherein the range of input frequencies is between 0.1 MHz and 4 MHz. 
     
     
       7. The method of  claim 1  wherein the signal generator and the signal processor are configured on a chip, with a processor and memory. 
     
     
       8. A non-transitory computer-readable medium having computer-executable instructions thereon for a method, the method comprising:
 by a signal generator and a signal processor,
 sending an input signal to a first input transducer, 
 
 wherein the first input transducer is contacting a gemstone under evaluation; 
 receiving a resonance signal from a second receiver transducer,
 wherein the second receiver transducer is contacting the gemstone under evaluation; 
 
 stepping the input signal through a range of input frequencies at a 200 Hz interval, from a range either greater than 1 MHz if the gemstone is less than one carat size, or from a range less than 1 MHz if the gemstone is greater than one carat in size;
 receiving a range of received signals; 
 
 processing, with algorithms, the range of received signals;
 determining, by the computer, resonant frequencies of the gemstone by identifying spikes of highest peaks in the display of all positive values; 
 determining how many crystals are included in the gemstone by counting the identified spikes of highest peaks in the display of all positive values; 
 determining a Q rating using the received signals wherein Q is defined as the center frequency of a peak divided by the full width at half maximum of the peak; 
 establishing a unique fingerprint for the gemstone based on the range of received signals and the Q value; 
 determining a weight approximation of the gemstone using a square root of a mass divided by two for a lowest resonance frequency spike detected; and 
 sending the processed range of received signals for the gemstone under evaluation to a computer for display and storage. 
 
 
     
     
       9. The non-transitory computer-readable medium of  claim 8  wherein the input signal is sent from the signal generator to the first transducer through an input amplifier; and
 wherein the received signal is received at the signal processor from the receiver transducer through a receiver amplifier. 
 
     
     
       10. The non-transitory computer-readable medium of  claim 8  wherein processing the received signal includes in-phase and quadrature components of the received signal. 
     
     
       11. The non-transitory computer-readable medium of  claim 8  wherein the signal processor includes a phase sensitive detector and digital signal processor. 
     
     
       12. The non-transitory computer-readable medium of  claim 8  wherein stepping the input signal through a range of input frequencies is stepped by 1 to 1000 Hz. 
     
     
       13. The non-transitory computer-readable medium of  claim 8  wherein the range of input frequencies is between 0.1 and 4 MHz. 
     
     
       14. The non-transitory computer-readable medium of  claim 13  wherein stepping the input signal through a range of input frequencies is stepped by 1 to 1000 Hz. 
     
     
       15. The non-transitory computer-readable medium of  claim 8  wherein the signal generator and the signal processor are configured on a chip, with a processor and memory. 
     
     
       16. A system, comprising:
 a chip, with a processor and memory, the chip configured as a signal generator and a signal processor, to
 send an input signal to a first input transducer, which may be amplified, 
 
 wherein the first input transducer is in contact with a gemstone under evaluation; 
 receive a resonance signal from a second receiver transducer,
 wherein the second receiver transducer, which may be amplified, is in contact with the gemstone under evaluation; 
 
 step the input signal through a range of input frequencies at an interval between 100 Hz and 300 Hz, from a range based on a size of the gemstone;
 receive a range of received signals; 
 process, with algorithms, the range of received signals; 
 determine, by the computer, resonant frequencies of the gemstone by identifying spikes of highest peaks in the display of all positive values; 
 determine how many crystals are included in the gemstone by counting the identified spikes of highest peaks in the display of all positive values; 
 determine a Q rating using the received signals, wherein Q is defined as the center frequency of a peak divided by the full width at half maximum of the peak; 
 establish a unique fingerprint for the gemstone based on the range of received signals and the Q value; 
 determine a weight approximation of the gemstone using a square root of a mass divided by two for a lowest resonance frequency spike detected; and 
 send the processed range of received signals for the gemstone under evaluation to a computer for display and storage. 
 
 
     
     
       17. The system of  claim 16  wherein the input signal step through a range of input frequencies is stepped by 100 Hz. 
     
     
       18. The system of  claim 16  wherein the process of the received signal includes in-phase and quadrature components of the received signal. 
     
     
       19. The system of  claim 16  wherein the signal processor includes a phase sensitive detector and digital signal processor. 
     
     
       20. The method of  claim 1  wherein the Q rating is peak frequency divided by full width at half maximum.